Abstract Air pollution is one of the largest global environmental risks to public health. Over recent years, neuroimaging techniques have started to uncover the detrimental impact air pollution has had on brain health, including the development of Alzheimer’s Diseases (AD). We systematically reviewed the literature to evaluate the effects of long-term exposure (months to years) to outdoor air pollutants on the development of AD-like neurology. This review was registered on PROSPERO (CRD42023482979) and followed PRISMA guidelines. Four large databases (MEDLINE, Embase, Scopus, and CINAHL) were searched in November 2023 using terms associated with air pollution, neuroimaging, and AD. Only peer-reviewed primary research articles using neuroimaging data to examine AD-like pathology after long-term exposure to air pollutants (Particulate Matter (PM2.5, PM10), SO2, NO2, O3, and/or CO) were included. Titles, abstracts and full-texts were screened, and included articles were quality assessed using the Newcastle Ottawa Scale. A narrative synthesis was conducted to analyse the studies. Our search yielded 397 results, of which eight articles met our inclusion criteria. Articles focused on changes to white matter (n = 5), cortical thickness (n = 6), and grey matter (n = 2). Exposure to PM2.5 was commonly associated with white matter reductions, and PM10 and NO2 exposure was associated with reduced cortical thickness. The effect of exposure to different outdoor pollution on grey matter was inconclusive, with both increases and decreases in grey matter volume observed. This review highlighted how PM2.5, PM10 and NO2 exposure was associated with neurological changes commonly seen in AD. These findings can be used by policymakers and researchers to identify specific pollutants that need greater restrictions and regulations to improve population health. Key messages • PM2.5, PM10 and NO2 exposure are associated with neurological changes commonly seen in AD. • Greater restrictions and regulations are needed on specific pollutants to improve population health.
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